Field of the Invention
The present invention relates to an image processing apparatus and a method for controlling the same, and particularly to an image processing apparatus that handles light field information and a method for controlling the same.
Description of the Related Art
Recently, image capture apparatuses that record not only the integrated intensity of light incident on pixel locations but also the intensity in each incident direction of light incident on pixel locations have been proposed, and such image capture apparatuses are called light field cameras (Ren. Ng, et al., “Light Field Photography with a Hand-Held Plenoptic Camera”, Stanford Tech Report CTSR 2005-02, 2005.4.20). For example, in a configuration in which a microlens array is disposed between an imaging lens and an image sensor so that a plurality of pixels of the image sensor receive light emitted from one microlens, the intensity of light incident on the microlens from a different direction can be obtained with each pixel.
Pixel signals (light field information) obtained in this manner have information on the intensity of incident light at a position of the microlens from the different direction. Therefore, an image (hereinafter, a refocus image) in which an arbitrary imaging plane is focused can be generated (reconstructed) by applying a method called “Light Field Photography”. Thus, in the case of imaging with a light field camera, it is possible to recognize and specify a subject that was not focused (or out of focus) at the time of imaging, by generating a refocus image.
It is known that additional information (also referred to as tags), such as personal names of persons in an image or an event name related to an image, is associated with image data in order to facilitate image searches. For example, assume that light field information is associated with additional information that is obtained from a plurality of refocus images that can be generated from the light field information and in which different distances are focused.
In the case where different light field information or an image (referred to as “derivative information”) is generated from light field information in this manner, the problem of which additional information should be attached to or associated with the derivative information arises. This is because in the case where the additional information associated with the original light field information is also associated with the derivative information as it is, additional information that does not correspond to the derivative information may be included.
For example, assume that all of names of subjects (herein, assumed to be persons) that can be specified in the refocusable range are associated with the original light field information as additional information, and a refocus image in which a specific distance is focused is generated as a derivative information. In this case, the additional information of the original light field information may include a name of a person who is not focused (i.e., a person who is out of focus) in the refocus image.